EP0216217B1 - Machine tool - Google Patents

Description

The invention relates to a machine tool with a variable-position workpiece table, in which a first area carries workpieces for processing by means of a tool of the machine tool in a first position as the processing side and in which a second area can be equipped with a further workpiece in a second position as the component side during processing is, the position of the areas is interchangeable by changing the position of the table and finally at least one splash guard element is arranged between the areas relative to the workpiece table.

Such a machine tool is known from DE-A 33 20 738.

The known machine tool is a so-called drilling and milling center with a vertical headstock, around which a plurality of tools are arranged and in which the tools can be successively exchanged into the receptacle of the headstock by means of gripper arms in order to produce a predetermined sequence on a workpiece mounted on the workpiece table to be able to carry out machining operations. For this purpose, the headstock can be moved in several axes relative to the workpiece table. In the known machine tool, the workpiece table is designed as a turntable, the axis of rotation being a vertical axis parallel to the spindle axis and being located in front of the spindle axis, as viewed by the user of the machine tool.

In the following, the sections of the workpiece table which can be moved in the area of the headstock or the user facing the headstock are to be referred to as the "area", the respective position of this area as the "position", the space above the area as the "work area" and the respective purpose of the areas in the different positions are referred to as "processing side" or "component side". In the known machine tool, the workpiece table is divided into two areas, and by rotating the workpiece table by 180 _° in each case, one area is located as a machining side in a position on the headstock and the other area as a component side is in a position for the user.

While a workpiece clamped there is being processed on the processing side, the user can already mount the next workpiece on the component side.

When machining a workpiece, however, care must be taken to ensure that the user of the machine tool is not contaminated by drilling fluid splashing around or even injured by metal chips flying around. In the known machine tool, the actual machine tool is therefore surrounded by an all-round closed covering cabin and in the area of the user there is a door which is hinged on its upper side, the suspension of which is designed so that the locus of its lower edge when the door is folded up over the outline of one workpiece and runs behind this outline down again. In the open position, the pivoting door thus forms a splash guard between the processing side and the component side.

However, this known arrangement requires a pivoting door which is suspended and can be guided on its upper side, so that this arrangement cannot be used if the covering of the machine tool on the component side has to be open at the top, for example to accommodate very heavy and / or bulky workpieces in a crane to drive the workpiece table.

Another problem with such machine tools is that, on the one hand, one wants to use the entire area of the area for clamping one or more workpieces, but problems can arise if the headstock moves with the tool on the machining side to close to the edge of the area , because the headstock cladding extends into the opposite area of the component side. In this case, the splash guard element would have to be arranged on the surface of the area on the component side so that the tool can move in the spindle axis up to the edge of the area on the processing side. However, if you now turn the workpiece table by 180 °, opposite demands arise, because the two areas are now reversed and the splash protection element should now be on the surface of the area that was previously positioned on the machining side. A solution to this contradiction is not provided for in the known machine tool.

The invention is therefore based on the object of further developing a machine tool of the type mentioned in such a way that free access to the workpiece table is possible from the component side, but at the same time effective spray protection for protecting the user between. Processing side and component side is guaranteed.

This object is achieved in that the splash guard element asymmetrically divides the work space defined by the areas, such that an area on the processing side occupies a larger work area than an area on the component side, that the splash guard element is arranged on the workpiece table and is movable so that if the positions of the areas are interchanged, the working area ratio of the areas on the processing side or the component side remains at least approximately constant and that the splash protection element is automatically movable with the change in position of the workpiece table.

The object underlying the invention is thus completely achieved.

According to the invention, the spray protection element, for example a solid splash protection wall, is independent of the respective position of the work table in such a way that a larger work space is available on the processing side, so that the headstock is far from being machined can be moved. When moving the table, however, the position of the splash guard element changes automatically with the movement of the table, so that no additional guide means from above are required. The component side remains completely free and can easily be approached, for example, with a crane that carries a heavy or bulky workpiece. The splash guard element, which is always arranged in the required position, for example the massive splash guard wall, automatically ensures that a relatively small angle is pivoted in the direction of the other workpiece table, and that the maximum deflection of the shielding takes place through the respective corner of the rectangular workpiece holder. After the rotation has been carried out, the shield swings back into its starting position, in which it rests on a longitudinal or narrow side of the workpiece holder and in this position lies outside the path of movement of the workpiece holder of the other shield. The shields mentioned only separate the two workpiece tables. For shielding to the outside, further shields reaching around the corner of the workpiece tables are required, so that the known arrangement as a whole is of complex construction and requires a series of movement processes, and in order to enable the workpieces to be equipped and machined in mutual play.

The invention is therefore based on the object of further developing a machine tool of the type mentioned in such a way that free access to the workpiece table is possible from the component side, but at the same time effective spray protection for protecting the user between the machining side and the component side is ensured.

This object is achieved in that the splash guard element asymmetrically divides the work space defined by the areas, such that an area on the processing side occupies a larger work area than an area on the component side, that the splash guard element is arranged on the workpiece table and is movable so that if the positions of the areas are interchanged, the working space ratio of the areas on the processing side or on the component side remains at least approximately constant and that the splash protection element is automatically movable with the change in position of the workpiece table.

The object underlying the invention is thus completely achieved.

According to the invention, the spray protection element, for example a solid splash protection wall, is independent of the respective position of the work table in such a way that a larger work space is available on the processing side, so that the headstock can be moved far towards the processor. When moving the table, however, the position of the splash guard element changes automatically with the movement of the table, so that no additional guide means from above are required. The component side remains completely free and can easily be approached, for example, with a crane that carries a heavy or bulky workpiece. The spray protection element, which is always arranged in the required position, for example the massive splash protection wall, ensures automatically and without any further control intervention that the user of the machine is reliably protected against drilling water splashes and flying metal chips.

The invention thus not only results in a larger area of application for the machine tool, even for heavy and bulky workpieces, it also increases the safety of the user.

In a preferred embodiment of the invention, the workpiece table is formed horizontally and can be rotated about a vertical axis, the splash guard element is arranged at least approximately parallel to and at a distance from the vertical axis in the first position, and when the positions are exchanged into a second position, the is Kiappsymmetrisch to the first position with respect to the vertical axis, shifted parallel.

This measure has the advantage that, in the case of a workpiece table which can be rotated about a vertical axis, as in the known machine tool of the type mentioned at the outset, a very simple division of the areas of the workpiece table can be achieved by means of an automatically moving splash protection wall.

In an alternative preferred embodiment of the invention, the workpiece table is formed horizontally and arranged to be rotatable about a vertical axis, splash protection elements are arranged on both sides of the vertical axis, of which the first splash protection element bordering on the component side is at least approximately vertical and the second splash protection element bordering on the processing side is the first splash protection element is arranged inclined, and when the positions are interchanged, the first splash protection element is inclined to the second splash protection element and the second splash protection element is moved into a vertical position.

This embodiment of the invention thus has the advantage that which is on the working side, inclined splash guard element is adapted to collect the herums ^p scribing drilling water and the flying metal chips and to run down, so that the space is protected between the two spray protection elements, and there a simple mechanism for the opposite movement of the two splash protection elements when rotating the table can be arranged, which is protected in particular from flying metal chips.

The fact that the working space on the processing side is somewhat reduced by the second, inclined splash guard element compared to the previously described embodiment, does not represent a significant disadvantage here because the Ver clothing of headstocks is usually also tapered down towards the tool, so that the inclined position of the splash guard element adapts to the likewise inclined covering of the headstock.

In the two embodiments described above, a particularly good effect is achieved in that a parallelogram guide is provided for moving the spray protection element (s), one of which is articulated on the workpiece table on a straight line intersecting the vertical axis and the other joint pair of which is the spray protection element (s) moves that a spring arrangement acts between the parallelogram guide and the workpiece table and exerts a restoring force on the parallelogram guide in a zero position in which the pairs of joints are at least approximately in alignment, that the parallelogram guide comprises an actuating lever which before reaching one of two by 180 ° with respect to the vertical axis End positions of the workpiece table offset from one another meet a fixed stop.

These measures have the advantage that a particularly simple, robust and automatic movement of the spray protection element or elements is possible. The parallelogram guide, which is automatically deflected via the actuating lever when the workpiece table is rotated by means of fixed stops, has only a minimum number of mechanical elements and is therefore extremely simple and unaffected by interference. The provision of the spring arrangement has the advantage that during the pivoting of the workpiece table in the area outside the fixed stops, the spray protection element or elements automatically move into a symmetrical zero position on the central axis of symmetry of the workpiece table and are only automatically deflected shortly before the end positions are reached , because the operating lever now comes into contact with one of the stops.

The parallelogram guidance described above can advantageously be further developed in the embodiment described above with only one splash protection element in that the other pair of joints carries the splash protection element.

This measure has the advantage that the splash guard element itself forms a rod of the quadrilateral joint of the parallelogram guide and thus only a minimum amount of actuating elements is required.

In the other embodiment with two mutually inclinable spray protection elements, the parallelogram guide, on the other hand, can advantageously be designed such that the other pair of joints comprises guide holes in rods which connect the spray protection elements to one another in the direction of inclination and are shorter than the distance between the spray protection elements.

This measure has the advantage that the mutually adjustable inclination of the splash protection elements in the inclination direction is realized by a trapezoidal four-bar linkage, which in turn is actuated by the second pair of links of the parallelogram guide. In spite of the greater complexity than in the first exemplary embodiment, this configuration also manages with a minimum number of actuating elements.

Further advantages result from the description and the attached drawing.

It goes without saying that the features mentioned above and those described below can in no way only be used in the respectively specified combination, but rather also in another combination or in each case alone, without departing from the scope of the invention defined by the patent claims. In particular, it goes without saying that the invention is in no way limited to machine tools with horizontal workpiece tables that can be rotated about a vertical axis; rather, it can also be used advantageously with workpiece tables that are guided differently, in particular tilted or shifted about any spatial axes.

• Fig. 1 ein Ausführungsbeispiel einer erfindungsgemäßen Werkzeugmaschine in einer Ansicht von oben, teilweise abgebrochen;
• Fig. 2 eine schematische Darstellung der Einzelheiten einer Parallelogrammführung zur Betätigung einer Spritzschutzwand einer erfindungsgemäßen Werkzeugmaschine;
• Fig. 3a bis 3c schematische Darstellungen von drei Phasen der Drehbewegung eines Werkstücktisches mit einer Parallelogrammführung gemäß Fig. 2;
• Fig. 4a und 4b eine schematische Ansicht eines Ausschnitts eines weiteren Ausführungsbeispiels einer erfindungsgemäßen Werkzeugmaschine in Seitenansicht und Draufsicht.

Embodiments of the invention are shown in the drawing and are explained in more detail in the following description. Show it:

• Figure 1 shows an embodiment of a machine tool according to the invention in a view from above, partially broken away.
• 2 shows a schematic illustration of the details of a parallelogram guide for actuating a splash guard wall of a machine tool according to the invention;
• 3a to 3c are schematic representations of three phases of the rotary movement of a workpiece table with a parallelogram guide according to FIG. 2;
• 4a and 4b show a schematic view of a section of a further exemplary embodiment of a machine tool according to the invention in a side view and a top view.

In FIG. 1, 10 denotes the front part of a machine tool, shown broken off, in a view from above. A headstock 11, indicated only schematically with its outlines, is designed to be movable in the plane of the drawing, as indicated by a second position 11 a. One can also see a workpiece table, designated as a whole by 12, which is designed such that it can be rotated back and forth by 180 _° about a vertical axis 13 running perpendicular to the plane of the drawing in the direction of a double arrow 14. The machine tool 10 is surrounded on all sides by a covering, the front part of which is designated 15 on the user side. The front cover 15 is interrupted by an opening 16 so that the user can stand at a point 17 in front of the machine tool 10 or a bulky and heavy workpiece can be moved from the front via this point 17 into the interior of the cover onto the workpiece table 12 by means of a crane can.

The surface of the workpiece table 12 is subdivided into a machining side 19 in the region of the headstock 11 and an equipping side 20 near the opening 16, and a middle section 21 is provided between these two. On the bear Processing side 19 shows an assembled workpiece 22, while on the assembly side 20 a further workpiece 22a can be assembled by the user in the outline shown there in dashed lines for subsequent processing. It can be seen that the workpieces 22, 22a do not exceed the surface of the processing side 19 or the component side 20.

The headstock 11 is spatially wider than the actual spindle 23 in the spindle axis 24, because a covering 25 of the headstock 11 is provided, which the drive elements, the gripping arms for changing the tools, a tool magazine and. the like. It is therefore clear that when machining the workpiece 22 on the machining side 19 to the assembly side 20 there must still be a certain amount of free space so that the headstock 11 can move so far that the spindle axis 24 can sweep over the entire surface of the workpiece 22. This free space is formed by the central section 21, which is free of workpieces 22, 22a.

In order to protect the user standing at point 17, who is currently assembling a workpiece 22a while the workpiece 22 is being processed, from drilling fluid splashing around and metal chips flying around, a splash protection wall 28 is arranged between the component side 20 and the central section 21. Due to this positioning of the splash guard 28, the headstock 11 can move up to the splash guard 28 with its cladding 25, as indicated by 11 a, and the spindle axis 24 can consequently sweep over the entire surface of the machining side 19.

However, it can also be seen that the splash guard 28 cannot be rigidly mounted in the position shown in FIG. 1, because when the workpiece table 12 is rotated through 180 _° it would come into a position 29, which would then be processed on the Machining side 19 located workpiece 22a would stand in the way.

The splash guard 28 is therefore designed to be movable, as will be explained below with reference to FIG. 2:

It can be seen that the splash guard wall 28 forms a long side of a parallelogram guide. A first lever 30 is arranged pivotably about the vertical axis 13 and holds the splash protection wall 28 at its free end in a joint 31. A second lever 33 is arranged pivotably about a further axis 32 spaced from the vertical axis 13 and also holds the splash protection wall 28 at its free end by means of a joint 34. In order to move the two levers 30, 33 synchronously, a rod 35 is provided which connects the levers 30, 33 to one another by means of joints 36, 37. As a result, the levers 30, 33 are designed as two-armed levers, with a first lever arm 41 holding the splash guard 28 and a second lever arm 42 leading to the rod 35.

The parallelogram guide is thus formed on the one hand by the surface of the table 12 with the first pair of joints 13/32, the two levers 30, 33 and finally the splash guard 28 on the second pair of joints 31/34. The rod 35 could be omitted per se, it essentially serves the purpose of not having to guide the required motive forces over the splash protection wall 28 during the movement of the parallelogram guide.

To actuate the parallelogram guide, a third lever 38 is rigidly formed on the second lever 33 as an actuating lever, which carries a roller 39 at its free end. In the position shown in FIG. 2, the roller 39 bears against a first fixed stop 40, which - with respect to the axes 13, 32 - is symmetrically opposed to a second fixed stop 40a.

In the vicinity of its axis of rotation 32, the third lever 38 has a further joint 43, on which a tension spring 44 engages. The other end of the tension spring 44 is fastened to a joint 45 which is located on a projection 46 of the workpiece table 12. The joint 45 and the axes 32 and 13 lie on a straight line 47.

The mode of operation of the parallelogram guide according to FIG. 2 will now be explained with reference to the movement phases shown in FIGS. 3a to 3c:

3a to 3c, one of the areas of the workpiece table 12 is designated by A and the other by B for clarification. In the starting position according to FIG. 3a, the area A is in the extent shown in dashed hatching on the component side and the area B on the processing side. The parallelogram guide with the elements 30 to 42 is in the one end position already shown in FIG. 2, and the same parts in FIGS. 2 and 3a to 3c are provided with the same reference numerals.

If the workpiece table 12 is now rotated into a position 12a according to FIG. 3b in the direction of an arrow 50, the roller 39 lifts off the first fixed stop 40. Under the action of the tension spring 44, the parallelogram guide now reaches a zero position in which the roller 39, the joints 45, 43, 32, 34, 13, 31 as well as the splash guard 28 lie on the straight line 47.

If the workpiece table 12 is now rotated from the position 12a according to FIG. 3b further in the direction of the arrow 50 into the end position 12b according to FIG. 3c opposite to FIG. 3a, the roller 39 comes into abutment with the second stationary one shortly before this end position 12b is reached Stop 40a, and the paralleiogram guide with its elements 30 to 42 clamps against the force of the tension spring 44 again in a position symmetrical to the position according to FIG. 3a. As a result, the splash guard wall 28 is again in a position shifted from the center to the component side 20, but areas A and B have now reversed their position.

4a and 4b show a further embodiment in side view and in a view from above.

The side view according to FIG. 4a shows the workpiece table 12, which has not been changed in this respect, with the machining side 19, on which the headstock 11 is located, and the component side 20. In contrast to the exemplary embodiment according to FIG. 1 4 to 3, however, in the exemplary embodiment according to FIG. 4, not a single splash protection wall, but rather two, which are designated by 60 and 61, are provided. The first splash guard wall 60 is arranged perpendicular to the surface of the workpiece table 12 in a position which corresponds to the position of the splash guard wall 28 in FIG. 1. Relative to the vertical axis 13, the second splash guard 61 is arranged symmetrically to the first splash guard 60. However, it is arranged inclined away from the processing side 19 and can, for example, touch the first, vertical splash protection wall 60 with its upper free edge.

As can be easily seen from Fig. 4a, the inclined arrangement of the second splash guard 61 means no significant loss of the work space in the area of the machining side 19, because the cladding 25 of the headstock 11 tapers down to the spindle axis 24 anyway, so that the spindle axis 24 can be moved up to the edge of the area on the processing side 19. On the other hand, the second, inclined splash guard 61 is, however, ideally suited to diverting splashes of drilling water or metal chips hitting it downwards without them being able to get into the middle section 21 between the splash guard walls 60, 61, in which the mechanism for the opposite movement of the splash guard walls 60, 61 is located.

In order to achieve this opposite movement, the splash protection walls 60, 61 are pivotally mounted on the surface of the workpiece table 12 in hinges 62, 63. At the same distance from the hinges 62, 63, joints 64, 65 are provided on the splash protection walls 60, 61 and are connected to a rod 66 or more parallel rods 66, 66a. The rod 66 therefore forms, with the joints 64, 65, the lower sections of the splash protection walls 60, 61, the hinges 62, 63 and the surface of the workpiece table 12 in the region of the central section 21, a trapezoidal quadrilateral joint. This quadrilateral joint can be pivoted into the position shown in FIG. 4a and also in a position symmetrical about the vertical axis 13, in which the first splash protection wall 60 is inclined and the second splash protection wall 61 are arranged vertically.

In order to bring about this back and forth movement synchronously with the rotation of the workpiece table 12 by 180 _° back and forth, a parallelogram guide is provided which largely corresponds to the parallelogram guide according to FIGS. 2 and 3 and which is shown in FIG. 4b. Corresponding elements of the parallelogram guidance are designated in FIG. 4b with the same reference numerals as in FIGS. 2 and 3, possibly supplemented by an apostrophe.

It can be clearly seen from FIG. 4b that the free ends of the lever arms 41 'and 41a' do not directly carry a splash guard, as was the case in the embodiment of FIGS. 2 and 3, rather the free ends engage in elongated holes 67 and 67a of two rods 66 and 66a; which connect the splash protection walls 60 and 61 to one another in the manner shown in FIG. ₄ a. When the workpiece table 12 is rotated in a direction which is indicated by an arrow 50 in FIG. 4b, the parallelogram guide first comes into the zero position under the influence of a tension spring which is not shown in FIG. 4b for the sake of clarity, in which - in the 4a - the splash protection walls 60, 61 together with the base defined by the central section 21 form an isosceles triangle. Shortly before reaching the second end position offset by 180 _° , the parallelogram guide is again clamped symmetrically in a direction opposite to the original direction, and the splash protection walls 60, 61 assume a position symmetrically opposite to FIG. 4a.

Claims (6)

1. Machine tool having a displaceable work table (12), comprising a first area (A), which in a first position in which it serves as the processing side (19), carries a workpiece (22) for being processed by means of a tool of the machine tool, and a second area (B) which in a second position in which it serves as the mounting side (20) can receive another workpiece (22a), the two positions of the areas being exchangeable by displacement of the table (12), and at least one splash guard (28; 60, 61) which can be moved relative to the work table (12) and which is arranged between the table areas (A, B), characterized in that the splash guard (28; 60, 61) subdivides the working space defined by the areas (A, B) asymmetrically so that an area (A) on the processing side (19) occupies a larger working space than an area (B) on the mounting side (20), that the splash guard (28; 60, 61) is arranged on the work table (12) and adapted to move in such a manner that the working space ratio between the area (A, B) on the processing side (19) and the area (A, B) on the mounting side (20) remains at least approximately constant when the positions of the two areas (A, B) are changed, and that the splash guard (28; 60, 61) moves automatically when the work table (12) changes its position.

2. The machine tool of claim 1, characterized in that the work table (12) is of horizontal design and arranged to rotate about a vertical axis (13) and the splash guard (28) extends, in a first position, at least approximately parallel to the vertical axis (13) and at a distance thereto and is subjected to parallel displacement when the positions are changed, and thereby moved to a second position mirror-symmetrical to the first position, relative to the vertical axis (13).

3. The machine tool of claim 1, characterized in that the work table (12) is of horizontal design and can be rotated about a vertical axis (13), that splash guards (60, 61) are provided on both sides of the vertical axis (13), with the first splash guard (60) provided adjacent the mounting side (20) being arranged at least approximately vertically and the second splash guard (61) provided adjacent processing side (19) being inclined relative to the first splash guard (60), and that the first splash guard (60) is in- dined relative to the second splash guard (61), and the second splash guard (61) is brought into a vertical position when the positions are changed.

4. The machine tool of any of claims 2 or 3, characterized in that a parallelogram guide (30 through 42) is used for moving the splash guard (28) or splash guards (60, 61) respectively, comprising one pair of joints (13/32; 13'/32') which is mounted on the work table (12) along a straight line (47) intersecting the vertical axis (13), and another pair of joints (31/34; 31'/34') moving the splash guard (28) or splash guards (60, 61) respectively, that a spring arrangement (43 through 45) acts between the parallelogram guide (30 through 42) and the work table (12) and exerts upon the parallelogram guide (30 through 42) a force tending to return it to a zero position in which the pairs of joints (13/32. 31/34; 13'/32', 31'/34') are at least approximately aligned with each other, and that the parallelogram guide (30 through 42) comprises an actuating lever (38) which abuts against a fixed stop before the work table (12) reaches one of two end positions which are set off by 1800 relative to the vertical axis (13).

5. The machine tool of claims 2 and 4, characterized in that the other pair of joints (31/34) carried the splash guard (28).

6. The machine tool of claims 3 and 4, characterized in that the other pair of joints (31'/34') comprises guide holes (67, 67a) of bars (66, 66a) interconnecting the splash guards (60, 61) in the direction of their inclination and being shorter in length than the distance between the splash guards (60, 61).

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